Summary: BRE 20823
A dorsolateral spinothalamic pathway in cat
MARK W. JONES, CHARLES J. HODGE, Jr., A. VANIA APKARIAN and RICHARD T. STEVENS
Department of Neurosurgery, Upstate Medical Center, Syracuse, NY13210 (U.S.A. )
(Accepted December 27th, 1984)
Key words: spinothalamic tract -- spinal lamina I-- pain
A spinothalamic tract that courses in the dorsolateral funiculus of the spinal cord and originates almost exclusivelyfrom spinal lami-
na I neurons has been demonstrated in the cat by retrograde transport of horseradish peroxidase. This tract is of special interest be-
cause the course of this predominantly lamina I, contralateral projection lies outside the classicalcourse of the spinothalamic tract and
because most lamina I cells contributing to the spinothalamic tract have been shown by other investigators to respond exclusivelyto so-
matic noxious stimuli. This newly described tract has important implications in the processing of noxious stimuli.
The spinothalamic tract (STT), classically consid-
ered to be confined to the ventral quadrant of the spi-
nal cord t7, conveys nociceptive and other sensory in-
puts22 from the periphery to the thalamus. The ST-I"
has been described to be made up primarily of axons
from cells within contralateral spinal laminae I and
IV-VIII 4,23 which cross segmentally in the spinal
cord and project predominantly to nucleus submedi-
us, the centrolateral nucleus, the ventral lateral nu-